FIG. 1 shows a portion of a prior art umbrella frame. Such an umbrella frame typically includes a plurality of umbrella struts 20 and umbrella ribs 30. Each umbrella rib 30 has an inner end 33 which is pivotally connected to an upper mounting ring 50. Each strut 20 has an inner end 27 which is pivotally connected to a lower mounting ring or umbrella runner 40. Each strut 20 has an outer end 28 which is pivotally connected to a midpoint of a corresponding rib 30. Upper mounting ring 50 is attached to the upper end of an umbrella central shaft (shown in phantom) while runner 40 is slidably received over the central shaft. Runner 40 and inner ends 27 of struts 20 are raised as shown to support ribs 30 in their open positions. Runner 40 is lowered (not shown) to close the umbrella.
Struts 20 and ribs 30 are connected to their respective mounting rings 40 and 50 by wires 10 which surround each mounting ring and which are received by apertures in inner ends 27 and 33 of struts 20 and ribs 30. Struts 20 are connected to the midpoints of ribs 30 by rivets 60.
Such connections are difficult and costly to fabricate, requiring special machinery for both wires 10 and rivets 60. In addition, typical umbrella frames are constructed of steel which is prone to rusting and which can become quite heavy as the size of the umbrella increases. The invention described below provides an umbrella frame which is easily assembled without special tools. Furthermore, the unique construction described is particularly compatible with light-weight plastic construction, thereby providing a much lighter weight umbrella frame than has generally been available.